12 The Bulletin. 



oiit from top to bottom. The moisture can thus move dowTi and up in 

 the soil to meet the needs of the crop throughout the season. It is 

 always observed, on well drained land, that the following year, when the 

 land has been plowed deeply again, and the layer of vegetable matter 

 torn up and mixed with the soil, that the "souring" effect disappears, 

 showing, if rightly interpreted, that it was the localization of the vege- 

 table matter and not the vegetable matter itself that produced the dele- 

 terious effect. 



Care must be taken not to turn under organic matter too deeply in 

 these soils, since the processes of decay go on very slowly below ten or 

 twelve inches. It has been found that the microflora or bacteria, etc., 

 that cause the organic matter of the soil to decay, and thus give rise 

 to the formation of the various nitrates in the soil, do not act freely 

 below nine or ten inches under the surface of heavy soils. 



It is also true that these all important organisms can not exist in the 

 first two or three inches of the surface soil on account of the too great 

 aeration and drying effect of the sun's heat. Their greatest activity, 

 therefore, is confined to that part of the soil stratum lying between 

 three and ten inches of the surface. 



ISTow these bacteria feed entirely on organic matter. An important 

 by-product of cattle feeding is the manure produced, but the principal 

 product of the feeding of the bacteria is the formation in the soil of 

 natural nitrates which are fundamental to crop production and which 

 are immediately available for the plant as soon as formed. If we cut 

 off the food supply from our cattle they die, and the same is true when 

 we cut off the food supply from our soil bacteria. It will be seen, 

 moreover, that the proper feeding of the soil bacteria is fundamental 

 to the feeding of cattle or any other farm animals as well as to the suc- 

 cessful production of crops. 



PLOWHSTG. 



These soils should be plowed at least eight and not over twelve inches 

 deep. Subsoiling might pay in preparing for corn which requires a 

 very large amount of water but in case deep plowing and turning under 

 of green manure is practiced, it will not usually be worth while to 

 subsoil for cotton. In general, subsoiling is doubtful economy in humid 

 climates on heavy soils not well filled with humus for the obvious reason 

 that when clayey soils, without humus, are loosened up to considerable 

 depth, the first hard downpour rushes through the soil into the depths 

 of the subsoil and fills it with water very quickly and in so doing the 

 soil particles previously loosened by the subsoil plow "run together" 

 and the subsoil becomes cemented and puddled again, and, on drying it 

 will be found as hard, compact, and impervious to moisture as before. 

 On the other hand, if the soil is filled with humus, the water falling 

 on the surface is caught and held in the upper three or four inches 

 of the surface and allowed to percolate more slowly down into the sub- 

 soil which is thus gradually filled with moisture and, at the same time, 

 the subsoil particles remain in a more or less open and porous condi- 

 tion and will thus receive and store a number of inches of rain during 



